英文關鍵字
air
atmosphere
background
bare
blue
boiler
building
business
chemical
chimney
closeup
cloud
cloudy
damage
ecology
emissions
energy
environment
environmental
factory
fume
fuming
funnel
global
heat
heating
industrial
industry
nature
pipes
plant
pollution
power
sky
smog
smoke
smokestack
smoking
stack
station
technology
tree
warming
winter